Author Topic: embedix questions  (Read 3286 times)

Harlequin

  • Newbie
  • *
  • Posts: 29
    • View Profile
embedix questions
« on: October 11, 2004, 11:19:19 am »
Hello,
I hope someone can help with this...

I was wondering what the difference between the linux kernel source on the zaurus and the full linux kernel source?

Was/is embedix a ground-upwards rewrite of the linux kernel, or is it a stripped down / patched specifically for the zaurus version?  Does Sharp maintain this kernel?

Do all zaurus kernels for a specific model use the same source?  I read somewhere that OpenZaurus is based on debian.  Does that mean that the usr/src on a debian install has the same kernel source as OpenZaurus (provided the kernels are the same version)?

If that's the case, why do people still use an older 2.4 release instead of a newer one?  Are the sources backwards compatible?  

Thanks,

Harry

lardman

  • Hero Member
  • *****
  • Posts: 4512
    • View Profile
    • http://people.bath.ac.uk/enpsgp/Zaurus/
embedix questions
« Reply #1 on: October 11, 2004, 11:34:12 am »
Quote
Was/is embedix a ground-upwards rewrite of the linux kernel, or is it a stripped down / patched specifically for the zaurus version? Does Sharp maintain this kernel?

Patched I believe; maintain is not really the word.

Quote
Do all zaurus kernels for a specific model use the same source? I read somewhere that OpenZaurus is based on debian.

Broadly speaking, yes; but some apply different patches to the kernel (the base kernel sources in all cases are the Sharp supplied ones).

Quote
Does that mean that the usr/src on a debian install has the same kernel source as OpenZaurus (provided the kernels are the same version)?

Not sure, put they will probably be similar bar the patches which are contained in the Sharp source tarball.

Quote
why do people still use an older 2.4 release instead of a newer one?

As 2.4.18 is the last one which Sharp produced (containing its device-isms and binary SD driver), it makes it a bit difficult starting from scratch and applying all of this stuff to a new kernel without their know-how. That said, work looks to be progressing reasonably well on 2.6.x for the Zaurii (see the openzaurus-devel and openembedded.org mailing lists).


Si
C750 OZ3.5.4 (GPE, 2.6.x kernel)
SL5500 OZ3.5.4 (Opie)
Nokia 770
Serial GPS, WCF-12, Socket Ethernet & BT, Ratoc USB
WinXP, Mandriva

Mickeyl

  • Hero Member
  • *****
  • Posts: 1495
    • View Profile
    • http://www.Vanille.de
embedix questions
« Reply #2 on: October 11, 2004, 11:48:56 am »
A kernel is something special, it's not like other parts of a distribution, since it's highly device specific. OpenZaurus is debian based, that means, the init structure, the filesystem layout, and things like that.

2.4.18-Embedix is the standard linux kernel (2.4.18) + Russels ARM patches + Nicos PXA patches  + a whole shitload of drivers of very questionable quality by the Lineo Japan team.

The most important ARM people have stopped working on 2.4.x - this is a deadend. Then again, the embedix patch is _huge_ and as I've said, of questionable quality. Pushing stuff forward is not easy, as it involves sanely rewriting many drivers, if you want to have the things accepted by mainline.

The only chance to see a 2.6 running on your Zaurus before the hardware gets hopelessly outdated and uninteresting, is to find more people joining John Lenz.

That said, since there doesn't seem that much people interested in even doing trivial stuff like maintaining packages or so for the Zaurus, I don't really expect to see kernel guys joining us.
« Last Edit: October 11, 2004, 11:53:02 am by Mickeyl »
Cheers,

Michael 'Mickey' Lauer | Embedded Linux Freelancer | www.Vanille-Media.de
Consider donating, if you like the software I contribute to.

Harlequin

  • Newbie
  • *
  • Posts: 29
    • View Profile
embedix questions
« Reply #3 on: October 11, 2004, 12:07:42 pm »
Thanks lads, that answers a lot of questions.

Last one.  If all the kernel implementations are based on the same source (and dubious drivers) why aren't zImages interchangeable across all roms for a specific model?  
Is it something to do with the compiler used? Or is it just that they have different options enabled and the rom is expecting specific device attributes that have been enabled by the compiler (either the software compiler, or the guy who decides to compile it    )?

Harry.

Harlequin

  • Newbie
  • *
  • Posts: 29
    • View Profile
embedix questions
« Reply #4 on: October 11, 2004, 12:27:37 pm »
Sorry, have answered this myself just by looking at any kernel release note.

Thanks,

Harry.

Chaos

  • Full Member
  • ***
  • Posts: 197
    • View Profile
    • http://zaurus.duelmonsters.ca
embedix questions
« Reply #5 on: October 11, 2004, 04:54:43 pm »
For anyone who's wondering, but don't feel like going for the release notes...

It's simply the different options used when compiling. The model, processor, video driver, sound driver are the main ones that are different. Most of the rest is the same.
Sorry. I just don't have the time...

jamesm

  • Full Member
  • ***
  • Posts: 102
    • View Profile
    • http://
embedix questions
« Reply #6 on: October 12, 2004, 06:53:12 am »
Quote
The only chance to see a 2.6 running on your Zaurus before the hardware gets hopelessly outdated and uninteresting, is to find more people joining John Lenz.

That said, since there doesn't seem that much people interested in even doing trivial stuff like maintaining packages or so for the Zaurus, I don't really expect to see kernel guys joining us.

At the recent LinuxWorldExpo in London last week, many of us got the chance to meet part of the emdebian team who were exhibiting all kinds of embedded devices happily running debian.

One of the showstoppers of the day for me (and many others) was a prototype version of the Psion Netbook PRO. This machine normally ships with Windows CE via Psion who aim the product at Business users in vertical markets (i.e. Stock control, medical etc).

Also exhibiting at the expo were a company called Xios, who have been working to market the Netbook PRO to corporate clients and business users, as a replacement for a laptop.

As part of this marketing bid, they have decided to base their OS on Linux and make the entire thing appeal to developers as well as corporate users. On display was a Netbook PRO happily running the 2.6.9 kernel and a rather fetching new GUI called the "Xios Desktop" iirc.

The magic of shoehorning the 2.6 kernel onto the psion was done by many of the emdebian team, who were contracted by Xios to do the work. What you're left with is a very capabable piece of hardware with a very nice looking OS.

I would not like to imagine how much it cost to contract the Kernel development work out to these talented kernel developers, although from the results it seems it was worth every penny. (The Xios marketing people were very excited about the response the machine was getting)

Unfortunately for us Z users/developers, we don't even have the corporate marketing backing of Sharp most of the time so I would be very suprised to see any Kernel bods working on the Z any time soon, unless they used the hardware or were paid to do so.
Victim of c3000 ebay scam.... Now after c3100

amrein

  • Sr. Member
  • ****
  • Posts: 345
    • View Profile
    • http://
embedix questions
« Reply #7 on: October 12, 2004, 07:41:34 am »
Any photos, reviews, web links, source to download... ?

jamesm

  • Full Member
  • ***
  • Posts: 102
    • View Profile
    • http://
embedix questions
« Reply #8 on: October 12, 2004, 10:35:05 am »
Quote
Any photos, reviews, web links, source to download... ?
I know George from #openzaurus on freenode took some photos of the psion netbook running the xios desktop, I'll try to get hold of them tonight and post them later when I'm home from work.

Xios were very cagey about release dates/schedules, the two machines they had running were very much 'proof of concept' and they were trying to generate some interest with the corporate types attending linux world. I'll try to find out some more later on this evening.
Victim of c3000 ebay scam.... Now after c3100